"The challenge is making sure they're all A-list players," says Craig Ulliott, chief technology officer. "My biggest mission is to do this while keeping the culture strong."

It's going to be a huge undertaking, said David Belsky, Chicago regional director at Jobspring Partners, a tech-recruiting firm based in Boston.

"It is going to be impossible to assemble 85 more A-level engineers," he said. "But they can find engineers who can become A-level after three to six months of getting familiar with the product and honing in on relevant skills. Companies looking to hire that much cannot look for reasons not to hire. They have to look for reasons to hire."

Mr. Belsky says software engineering has negative unemployment in Chicago, where candidates easily can get called in for three or four interviews within days of starting a job search.

"They have so much activity that it is tough to get them out to additional first-round interviews," he said. "Companies don't yet realize fully that the tech candidates have the upper hand. I am seeing jobs stay open for an average of three-plus months."

Jeremy Haney

But Mr. Ulliott isn't without resources. Belly CEO Logan LaHive hired Jeremy Haney, who spent the past three years hiring tech talent for Google Inc. And they've got plenty of money: Belly raised $12.1 million last summer from Andreessen Horowitz, NEA and other investors.

The company plans to offer $1,000 to any candidate to whom it offers a job, even if the person doesn't come to work for Belly. While Mr. Ulliott is looking for experienced talent, Belly also has a program to hire college grads and junior employees. Among the more difficult jobs to fill are experienced Javascript app developers.

Mr. Ulliott, who previously was CTO at social-networking travel startup Where I've Been, is adamant about building the technical team in Chicago.

"I have no plans to open a remote office on the West Coast," he says.

Belly, a three-year-old company launched by Lightbank, developed a digital version of the punch card for merchants that makes heavy use of tablets and smartphones. The platform has grown from small merchants to include large chains such as 7-Eleven.

"Rewards was only step one. Our long-term plan is the platform: the digital connection between merchants and members." Mr. Ulliott says. "You'll be seeing a lot more happening on the iPad and mobile. We're adding more tools for merchants, and there will be a lot of member-facing features."